TH400/D20 strength and mounting?

[Langdon]

I plan on swapping to this combo, but I'm thinking twice since both Porkchop and RiverBeast have recently broken the transmission tailhousing with the same setup. The tailhousing has somewhat of a rep for being weak (of course Novak will say this because they want to sell their stuff), what do some of the others running this combo think?

PC, RB: Could you describe the circumstances when yours broke, and can you pin down the cause?

One thing that crossed my mind is the xfer mounting: IIRC I saw a pic of RiverBeast's mounted with the QuadraTrac hardware...LIKE THIS (http://www.windrockoffroad.com/show_plate.asp?PlateNo=5944). The stock mounting setup is LIKE THIS (http://www.windrockoffroad.com/show_plate.asp?PlateNo=5945). Could this contribute to breakage? PC how did you have yours mounted?

Thanks for the help,

[FSJeeper]

It is the large wheels and tires, high lift, and pinion angles that put extra stress and the tcase adapter and break it. This is a common situation with these circumstances.

[porkchop]

Well I have mine mounted with a combo of both. It is hard to explain. It makes it stronger. Mine broke around the adapter itself. Not the mounting tabs. Mine broke when the u-joint gave out and tweaked the t-case. There where some pics on here awhile ago. I would post some more but not at home. I am working on a "new" mounting system. Both me and RB. We hope to have it done soon. It will eliminate the original mounting design. We will keep everyone posted of course.

Novaks are stronger. It is made from a stronger aluminum and has stronger mounting tabs. It is $200 for the adapter alone.

[Tad]

Properly mounted and tightened there is nothing wrong with this set up at all.
When I swap mine with the broken tab for the new one I'll also be breaking out the TIG welder to design a better setup also.
I'm thinking larger base with gussets and some tieins from the new base to the top. ;)

[River Beast]

one of my problems, besides the lift and angles contributing to stress is a mismatch mount setup....I could be wrong here... but poly is not as 'forgiving' as rubber... I have a poly T-case mount and rubber motor mounts... the torque can be seen in the motor mounts as you rap the throttle... the poly Tcase mounts doesn't budge.

that is problem #1

Keep in mind that #1 contributes to the remainder of the post.

the mounting bolts are only 3/8" bolt going thru tapped alluminum.... heavy wheeling and vibes with eventually work them loose....they do come loose. CHECK THEM PRIOR and AFTER a 4x4 ADVENTURE!!!!

If you fail to check them and they are loose, the torqueing of the motor/tranny/t-case takes it's tole on the mounting ears of the adapter and could possibly strip the ears... one of the ears on my adapter was stripped... I anchored it down with longer 3/8" bolts, lock washers and nuts on top of the ear on both sides. to ensure a strong mounted surface... apparently not strong enough.

After the stripped side became loose the torqueing of the motor began to raise up on the loosen bolt side and put undue stress on the solidly mounted side and eventually snapped the ear off....

Partly my fault for not looking MORE CLOSELY (like with a wrench) prior to hitting Imogene Pass...

As for the strengthening of the D20 mounting... PC and will talk and get something going... I bought some material this weekend to start on my ideas whcih should be simple enough for ANYONE to do with a few common handtools.

IMHO... 2 3/8" bolts is just not enough to hold power on 2 ears that are barely 1/2" thick when you modify your 4x4 to the levels that we have. more evenly distributed holding points will enhance the security and life of the D20 adapter... I'm sure of it...I will be using the same borken eared adapter to make the mods for strenghtening... prolly use it to.... I won't have any doubts about it holding when I'm done.... until I break it again.... hehehe I doubt I will though.... ;)

[Langdon]

Thanks for the replies...any other experiences out there? I'm curious to see what you come up with RiverBeast--does this guy ever quit?? :cool: :D

[porkchop]

Hey, RB, I am on duty right now but I will give you a call at the house tomorrow night to se what you came up with. I started on mine yesterday, planning stage, and we will have to compare.